Sliding and locking the forging tools on a forging press

ABSTRACT

A preferably horizontally-acting forging press has forging tools slidably mounted on the forging pistons so that the tools can move up and down, the tools having two different forging zones, and a hydraulic device for locking the forging tools with one or other of their forging zones in the working position of the press.

' United States Patent Schmoll et al.

SLIDING AND LOCKING THE FORGING TOOLS ON A FORGING PRESS Inventors: Heinz Schmoll, Huckeswagen;

Dieter Jenke, Gruiten, both of Germany Schloemann Aktiengesellschaft, Dusseldorf, Germany Filed: May 29, 1973 Appl. No.: 364,241

Published under the Trial Voluntary Protest Program on January 28, 1975 as document no. B 364,241.

Assignee:

Foreign Application Priority Data May 26, 1972 Germany 2225528 US. Cl 72/407; 72/447 Int. Cl. B21J 13/00 Field of Search 29/l.5; l0/ll A, 12 R,

[ Nov. 4, 1975 [56] References Cited UNITED STATES PATENTS 667,187 2/1901 Carstens 10/12 R 1,024,046 4/l9l2 Weeks 4 l0/l2 R 2,245,642 6/1941 Bell et al.... 72/447 3,472,058 l0/l969 Hautau 72/407 3,477,075 11/1969 Putetti lO/l2 R FOREIGN PATENTS OR APPLICATIONS 1,296,596 6/1969 Germany Primary ExaminerC. W. Lanham Assistant ExaminerE. M. Combs Attorney, Agent, or FirmH0lman & Stern [57] ABSTRACT A preferably horizontally-acting forging press has forging tools slidably mounted on the forging pistons so that the tools can move up and down, the tools having two different forging zones, and a hydraulic device for locking the forging tools with one or other of their forging zones in the working position of the press.

7 Claims, 2 Drawing Figures US. Patent Nov. 4, 1975 3,916,668

L\ I 6 a 79 SLIDING AND LOCKING THE FORGING TOOLS 4 ON A FORGING PRESS BACKGROUND OF THE INVENTION The invention relates to a device for sliding and locking the forging tools (which may be referred to as saddles or tups) on a forging press, particularly on a horizontally acting forging press, and to the forging press itself.

Fully automatic devices for changing the forging tools are already known in the'field of open-die (as opposed to closed die) forging presses. However, on horizontallyacting forging presses, changing the working positions of forging tools having different forging zones (i.e., working impressions) hitherto required a substantial amount of time after shutting down the press.

THE INVENTION The present invention provides a forging press having:

at least two forging piston-cylinder units .(which may be referred to as forging-rams) for making the forging-strokes; 1

at least two forging'tools, each tool having at least two different forging zones (conveniently adjacent oneanother), the tools being slidably mounted on the moving parts (preferably the pistons) of respective forging piston-cylinder units but being slidable with respect thereto in a direction at right angles to the forging direction (i.e., in a direction at right angles to the axis of the forging pistoncylinder unit) in order to change the forging zones which are in the working position; and

hydraulic means for locking the forging tools in their respective working positions.

The invention also provides a device for sliding and locking a forging tool, for a forging press having a plurality of piston-cylinder units and respective forging tools mounted on the piston-cylinder units, the device including a forging tool which has at least two different forging zones and which is slidably mounted on the piston-cylinder unit so as to be slidable with respect thereto in a direction at right angles to the forging direction in order to change the forging zone which is in the working position, and hydraulic means for locking theforging tool in the respective working position.

lf,-as is preferred, the forging press is horizontally acting, the forging tools preferably slide vertically, the forging zones on each tool being one above the other.

Using the invention, the individual forging zones on the forging tools can be changed to suit the crosssection of the workpiece without any substantial interruption of the forging operation. The required forging zone may be automatically moved into the working positionand locked therein.

There may be respectivestationary rams for engaging the forging tools when they are in their retracted positions and for moving them in said direction at right angles to the forging direction, and the limiting position of the rams can be adjustable. If the forging tools slide vertically, the stationary rams can be for abutting the undersides of the respective forging tools. For each forging too|,the hydraulic locking meanscan comprise a locating and a clamping piston-cylinder unit disposed in or on the moving part of the respective forging piston-cylinder unit, the locating piston-cylinder unit being for locating the working tool in a said working position and the clamping piston-cylinder unit being for clamping the working tool in a said working position. It is convenient for both the locating and the clamping piston-cylinder units tobe connectable to a constantpressure retraction duct for supplying hydraulic fluid for retractingthe moving part of the respective forging piston-cylinder unit.

A compression spring, preferably positioned between the rear of the respective cylinder and the respective piston, can be provided for acting against the hydraulic pressure of the respective unit for disengaging the location and the clamping. 1

In general, both -the locating and the clamping pistoncylinder unit can have a piston rod on which is mounted a respective locating or clamping element. The locating piston-cylinder unit can have a locating bolt mounted on its piston rod for entering a corresponding aperture in the respective forgingtool, and the clamping piston-cylinder unit can have a clamping wedge mounted on its piston rod, for engaging a part I of the forging tool, the forging tool being received in and slidable in a dove tail section guide in the movable part of the forging piston-cylinder'unit.

BRIEF DESCRIPTION OF THE DRAWING One embodiment of the invention is particularly described, by way "of example, with reference to the accompanying drawing, in which:

FIG. I is one side of a horizontally acting forging press, mainly in section along the line [-1 of FIG. 2;

and

FIG. 2 is a plan view, partially in section, of a forging cylinder and clamping device for the forging tup of the forging press of FIG. 1.

PARTICULAR DESCRIPTION OF PREFERRED EMBODIMENT The forging press has a press frame (not shown) to which are fixed two horizontal axis forging cylinders, of which the left-hand cylinder 1 is shown in the drawing. The press may be the forging press described in copending Application Ser. No. 356,452 entitled Hydraulic Forging Press, filed May 2, 1973, now US. Pat. No. 3,847,008. The forging press has retraction means in the form of retraction cylinders (not shown) which are constantly under hydraulic pressure; although this arrangement correspondingly reduces the effective forging force, the arrangement can facilitate faster speeds. The constant hydraulic pressure can however be shut off, in a conventional manner. A respective forging piston or plunger 2, which is stepped and is provided with a piston shank 3, extending rearwardly through the rear of the cylinder, slides in each forging cylinder 1. The forging piston 2 is guided by the front end of the forging cylinder 1 and the piston shank is guided by the rear end of the forging cylinder 1, giving guidanceat two spaced positions. Retracting means (not shown) act on the piston shank 3. The retracting means can be conventional.

The horizontally acting forging piston 2 is provided on its front end.face with a vertically extending guide way 4 of dove-tail construction and in which a forging tup (forging tool) 5 is vertically slidable. On its front side (the side nearest to the workpiece or forging) (not shown), the forging tup 5 is provided with two different forging impressions or zones 6 and 7.

A double-acting ram piston 9, whose piston rod 10 moves the forging tup 5 up and down, slides in a vertical cylinder 8 having ports 8a and 8b; the cylinder 8is mounted on the forging cylinder 1 such that the piston rod 10 can abut the forging tup 5 when the forging piston 2 is fully retracted. The end position of the free end of the piston rod 10 may be adjusted by means of a screw-threaded bolt 10a.

A single-acting locating cylinder 11, in whose bore slides a locating piston 12 having a piston rod 13, is provided axially of the forging piston 2. A compression spring 14 surrounds the piston rod 13 and bears against the piston 12 as well as against the cylinderl l and acts in the opposite direction to the piston 12. The locating cylinder 11 is connected through a single duct 15 in the forging plunger '2 to the constant pressure of a retractionvduct for the forging piston 2. The piston rod 13 is provided with an engagement member in the form of a locating bolt 16 which engages in corresponding apertures 17 or 18 in the forging tup 5, respectively associated with theindividual forging impressions 7 and 6.

The upper front end of the forging'plunger 2 is also provided with a recess 19 for engagement with a stop 20 on the forging tup 5 when the tup 5 is in its lowermost position. I

The forgingpiston 2 is also provided with a horizontally-acting, single-acting clamping cylinder 21, perpendicular to the locating cylinder 11 and having a bore in ,which slides a clamping piston 22. Its piston rod is provided with an engagement member in the form of a clamping wedge 24 which engages the part of the forging tup 5 .which is in the dove-tailed guide 4. A compression spring 25 surrounds the pistonrod 23 with one end bearing against the piston 22 and the other end bearing against the cylinder 21, and acting against the piston 22. The clamping cylinder 21 is also connected through a duct 26 to the duct 15 and hence to the constant pressure of the retraction ,duct of the forging plunger 2, thereby requiring only a single delivery duct 15 in the shank 3 of the forging piston 2, I

The compression springs 14 and 25 therefore act against their respective pistons 12 and 22 and retract the appropriate locating bolt 16 or the clamping wedge 24 from the forging tup 5 when the hydraulic pressure, which otherwise acts continuously on the pistons 12 and 22, is shut offf The pistons 12 and 22 and associated parts provide hydraulic locking means. Method of operation i device, which is not shown, inserts the forging tup 5 downwards into the guideway 4 and lowers the forging tup 5 onto the piston rod 10 of the piston 9. Opening the duct 15 to the continuous, constant retraction pressure and pressurising the locating or clamping pistons 12 and 22 causes the forging tups 5 to be located and clamped in position. One therefore uses for the locking a source of hydraulic pressure which is already available, i.e., that which is used for retraction. The forging tup 5 is then ready for the forging operation. After the completed forging operation, the forging piston 2 stops in its rear limiting position. The clamping and locating of the forging tup Sis released by the force of the compression springs 14 and 25 when the hydraulic pressure is shut off. The piston 9 can then lower the forging tup 5 until the stop 20 abuts the bottom of the recess 19. The forging tup 5 is then located and clamped inthis position. The finish forging impression 6 is then ready for use 1 We claim: I 1. In a forging press having a press frame, forging piston-cylinder units each having a fixed part mounted on the press frame and a movable part for effecting forging strokes, retraction means for retracting said movable part, said retraction means comprising a constantpressure retraction duct for applying hydraulic fluid for retracting said movable part, a forging tool mounted on said movable part, said forging tool defining a plurality of forging zones, the provision of a forging tool moving and locking arrangement comprising means on each said forging tool and said movable part for permitting movement of said forging tool relative to said movable part, in order to position each forging zone in a selected working, position, and hydraulic means for locking said forging zones in their respective working positions, said hydraulic means comprising for each said forging zone, at least one engagement member for engaging said forging tool and locking said forging tool, a single-acting locking piston-cylinder unit mechanically connected to said engagement member for actuating said engagement member to engage and lock said forging tool, hydraulic duct means connecting said locking piston-cylinder unit to said constantpressure retraction duct, and spring means for retracting said engagement member when said locking pistoncylinder unit is not subjected to hydraulic pressure.

2. An arrangement as claimed in claim 1, wherein said moving and locking arrangement comprises, for said forging tool, a stationary ram for engaging said forging tool when it is in its retracted position and for moving said forging tool relative to said movable part.

3. An arrangementas claimed in claim 2, wherein said forging press is a horizontally-actingpress,wherein said forging tool slides vertically with respect to respective said movable parts, said forging zones on said forging tool are one above the other, and said stationary ram abuts the underside of the forging tool.

4. An arrangement as claimed in claim 1, wherein said spring means comprises in said locking-pistoncylinder unit, a compression spring between the rear of the respective cylinder and the respective piston, said spring acting against the hydraulic pressure of the respective said unit, for disengaging said locking cylinder unit.

5. An arrangement as claimed in claim 1, wherein there is a plurality of said engagement members each associated with a respective said locking pistoncylinder unit, a saidhydraulic duct means and the said spring means, one said engagement member being a locating bolt, and another said engagement member being a clamping wedge, said forging tool including apertures corresponding to said forging zones for receiving said bolt, said means for permitting movement of said forging tool comprises a dove-tail slot in said movable part and a part of the forging tool received in and slidable in said slot, and said clamping wedge being for engaging said part of said forging tool received in the dove-tail slot. 2

6. An arrangement as-claimed in claim 1, wherein said engagement member is a clamping member for clamping said forging tool in a selected working position.

7. An arrangement as claimed in claim 2, wherein said engagement member is a clamping member for clamping said' forging tool in a selected working position. 

1. In a forging press having a press frame, forging pistoncylinder units each having a fixed part mounted on the press frame and a movable part for effecting forging strokes, retraction means for retracting said movable parts, said retraction means comprising constant-pressure retraction ducts for applying hydraulic fluid for retracting said movable part, a forging tool mounted on said movable part, said forging tool defining a plurality of forging zones, the provision of a forging tool moving and locking arrangement comprising means on each said forging tool and said movable part for permitting movement of said forging tool relative to said movable part, in order to position each forging zone in a selected working position, and hydraulic means for locking said forging tools in their respective working positions, said hydraulic means comprising for each said forging zone, at least one engagement member for engaging said forging tool and locking said forging tool, a single-acting locking piston-cylinder unit mechanically connected to said engagement meMber for actuating said engagement member to engage and lock said forging tool, hydraulic duct means connecting said locking piston-cylinder unit to a constantpressure retraction duct, and spring means for retracting said engagement member when said locking piston-cylinder unit is not subjected to hydraulic pressure.
 2. An arrangement as claimed in claim 1, wherein said moving and locking arrangement means comprises, for each said forging tool, a stationary ram for engaging said forging tool when it is in its retracted position and for moving said forging tool in said direction at right angles to the respective said forging stroke.
 3. An arrangement as claimed in claim 2, wherein said forging press is a horizontally-acting press, wherein said forging tool slides vertically with respect to respective said movable parts, said forging zones on said forging tool are one above the other, and said stationary ram abuts the underside of the forging tool.
 4. An arrangement as claimed in claim 1, wherein said spring means comprises in each of said locating piston-cylinder unit and said clamping piston-cylinder unit a compression spring between the rear of the respective cylinder and the respective piston, said spring acting against the hydraulic pressure of the respective said unit, for disengaging said locating and the clamping units.
 5. An arrangement as claimed in claim 1, wherein said locating piston-cylinder unit has a piston rod on which is mounted a locating bolt, said forging tool including apertures corresponding to said forging zones for receiving said bolt, said means for permitting movement of said forging tool comprises a dove-tail slot in said movable part and a part of the forging tool received in and slidable in said slot, and another clamping piston-cylinder unit having a piston rod on which is mounted an engagement member in the form of a clamping wedge, for engaging said part of said forging tool received in the dove-tail slot.
 6. An arrangement as claimed in claim 1, wherein said hydraulic locking means further comprises a clamping piston-cylinder unit including means for clamping said forging tool in a selected working position.
 7. An arrangement as claimed in claim 2, wherein said hydraulic locking means further comprises a clamping piston-cylinder unit including means for clamping said forging tool in a selected working position. 